Gunner compartment



March 10, 1936.

D. M. HELW IG GUNNER COMPARTMENT Filed Oct. 15, 1932 Sheets-Sheet 1 INVENTOR. DREW M Haw/e A TTORNE Y.

March 10, 1936.

D. M. HELWIG GUNNER COMPARTMENT Filed 0013.15, 1932 2 Sheets-She et 2 INVENTOR.

.DREW M. HELW/G A TTORNE Y.

Patented Mar. 10, 1936 UNlTED STATES GUNNER coMPAa'rMnN'r Drew M. Helwig, Overlea, Md., assignor to The Glen L. Martin Company, Baltimore, Md.

Application October 15, 1932, Serial No. 63?,875

My invention relates to airplanes of the combat type and has particular reference to a construction in which the gunner is not subjected to the high air pressures that are associated with diving operations.

A gun can be effectively aimed and fired from an airplane by an exposed gunner within certain limits of air speed, but while either flying or diving at the high speeds attained by modern types of combat airplanes the air pressure is of 'such magnitude that it is'impossible for him to efilciently attack a target. Turrets have heretofore been provided for gunners, but they were inadequate to meet the severe conditions that are imposed by high air speeds.

The principal object of my invention therefore is to increase the efficiency of a combat airplane.

Another object .is to provide a turret equipped compartment wherein the gunner is not subjected to the blasts of air that are associated with high air speeds.

Another object is to provide a safety exit for the gunnerwhile in flight.

The accompanying drawings are briefly described as follows:

Fig. 1 is a side elevation of my airplane that is equipped with a forwardly located turret and a gunner compartment that is equipped withdual emergency exits.

Fig. 2 is a front view of the airplane shown in Figure l.

Fig. 3 is an enlarged view of the trap-door shown in Figure 1 together with a manually operable door latch and hinge'release mechanism.

Fig. 4 isan enlarged view of one of the hinge pin mechanisms shown in Figure 3. I The air speeds which are associated with combat airplane'maneuvers are of such high magnitude that the. resulting air-blast through a turret aperture into a conventional compartment will hamper the gunner in the performance of his duties, and also seriously impair his target hitting efliciency, unless an effective counter-acting pressure is provided.

The invention herein set forth provides a gunner compartment in the nose of an airplane, which location subjects it to positive air pressures of considerable magnitude while flying at high speed with particular reference to diving-maneuvers', the compartment including a forwardly mounted gun turret having a transparent wall for general observation by the gunner as well as visual communication with the pilot, the wall being apertured into the positive pressure area for gun firing purposes, and the compartment being otherwise substantially air tight. The sides of the aperture are adapted to track a carriage upon which a gun may be swivel mounted so that it can bequickly and efliciently aimed and fired 5 either downwardly or upwardly as well as later ally within the limitations of the aperture; and by revolving the turret more or less as required the field of fire can be efiectively directed while maneuvering the airplane. A seat for the gun- 1O ner'is attached to the turret base so that he can maintain his position relative 'to the gun while revolving the turret. Airblast interference with the gunner, which has heretofore been associated with conventional arrangements of turrets and the like in high speed airplanes, is prevented by a counter-pressure that is automatically built-up as the direct result of airspeed reactions through the aperture into the otherwise substantially air tight compartment.

The turret apex projects somewhat above the upper surface of the fuselage in order to provide for gunner-pilot visual inter-communication, and also to eliminate the sense of personal isolation that would otherwise be engendered by the enclosed gunner compartment.

A forwardly latched and rearwardly hinged trap-door is provided in the bottom of the compartment for ingress and particularly for safe egress under emergency conditions. The latch is manually operable from either the inside or outside of the compartment, and the hinges are so constructed that the door can be completely detached from the fuselage structure. A release cable is connected; to both latches and to the hinge pins so that the gunner can jettison the door in advance of leaving the compartment while flying to thereby insure himself against in-= jury by an otherwise swinging door. The aforesaid air pressure within the compartment while flying, and particularly while diving at high a speed materially assists in jettisoning the door.

' The accompanying drawings depict a preferred form of the invention, but it is obvious that variations within the scope of the claims can be made by persons skilled in the related arts.

Referring to the drawings:

Fuselage In of a combat airplane is provided with a gunners compartment H, a pilots position l2, and a substantially air tight bulkhead I3. An emergency exit is provided in the top of the compartment so that the gunner can escape in the event of a crash. The exit is normally closed by a substantially air tight door M. A turret 95 having an aperture i6 is mounted upon the fuselage structure in communication with compartment II. A gun I! is suitably mounted upon the turret for convenient operation by the gunner. A seat I8 for the gunner is attached at the base-of the turret.

A substantially air tight trap-door 25 is hinged to the fuselage structure at the bottom of the...

compartment by a pair of arms 26 and a pairof retractable hinge pins 21. The pins are urged by spring 28 into engagement with the arms. Latches 29 are urged by spring 30 to aposition for latching the door in closed relation to the compartment. A handle 31 is connected by cable 32 to the latches so that the door can be'opened from outside the compartment, and a handle 33 is connected by cable 34 to the latches so that the door can be opened from inside the compartment. The door is preferably provided with toeholds 35 to facilitate entering the compartment from the ground when the door is opened. A handle 36 is connected by cable 31 to cable 34, and also by cable 38 to pins 21; so that the latches and the hinge pins can be simultaneously released to completely detach the door from the fuselage structure. Pulleys 39 are provided for the cables where required. The door having been jettisoned; an exit is provided that is free from obstruction; particularly while diving in a more or less vertical direction.

I claim:

1. In an airplane having a fuselage; a gunner compartment in the nose of said fuselage, the compartment being apertured into the positive pressure area; and means including a partition between the said. compartment and the remainder of the fuselage whereby the compartment is substantially air tight except for said aperture.

2. An airplane as defined in claim 1 in which said means includes a door for ingress and egress.

3. An airplane as defined in claim 1 in which said means includes a rearwardly hinged and forwardly latched door for ingress andegress; and means operable by the gunner to operate the latch.

4. An airplane as defined in claim 1 inwhich said means includes a latched and hinged door for ingress and egress, the hinge being separable, and means operable by the gunner to operate the latch and separate the hinge to completely detach the door.

h 5'. In an airplane having a fuselage; a gunner compartment in the nose of said airplane, the compartment including a streamlined gun turret the wall of which is faired to the fuselage as well as apertured into the positive pressure area; and means including a partition between the said compartment and the remainder of the fuselage.

whereby the compartment is substantially air tight except for said apertur 6. An airplane as defined in claim 5 in which said means includes a door for ingress and egress. 7. In an airplane having a pilot position; a gunner compartment in the nose of said airplane, the .compartment ,being apertured into the positive pressure area; and means including a partition between the said compartment and the said position whereby the compartment is substantially air tight except for said aperture.

8. An airplane as defined in claim 7 in which the said means includes a door for ingress and egress by the gunner.

9. An airplane as defined in claim 'I in which the said means includes a transparent wall for visual communication between the gunner and the pilot and also a door. for ingress and egress by the gunner. 10. In an airplane having a pilot position; a gunner compartment including a 'gun turretin the nose of said airplane, the turret being apertured into and revolvable within the positive pressure area; and means including a partition between the said compartment and the said position whereby the compartment is substantially air tight except for said aperture, the means also including a transparent wall for visual communication between the gunner and the pilot.

11. In an airplane having a pilot position; a gunner compartment in the nose of said airplane, the compartment including a gun turret having a transparent wall which is apert "d into the positive pressure area, the wall providing for general observation and visual communication with the pilot; and means including a partition between the said compartment and the said position whereby the compartment is substantially air tight for said aperture.

12..In an airplane having a pilot position; a

gunner compartment in the nose of said airplane,

the compartment including an apexed. turret having a transparent wall, the wall being apertured 13. In an airplane; a gunner compartment in the nose of said airplane, the compartment being apertured into the positive pressure area; means including a partition between the said compartment and the remainder of the airplane whereby the compartment is substantially air tight except for said aperture; said means also includinga door for ingress and egress, the door being hinged and latched; whereby thepositive air pressure built up within thesaid compartment 'by airspeed will facilitate opening the door when unlatched for egress by the gunner while in flight.

14. In an airplane; a gunner compartment in the nose of said airplane, the compartment being apertured into the positive pressure area; means including a partition between the said compartment and the remainder of the airplane whereby the compartment is substantially air a tight except for said aperture; said means also including a door for ingress and egress, the door being latched and rearwardly hinged: whereby the positive airpressure built up within the said compartment by airspeed will facilitate opening the door rearwardly when unlatched for safe egress by the'gunner while in flight.

the positive airpressure built up within the said compartment by airspeed will facilitate opening the door and the airflow forwardly adjacent the opened door will swing the door rearwardly for safe egress by the gunner while in flight.

16. In an airplane; a gunner compartment in the nose of said airplane, the compartment being apertured into the positive pressure area;

means including a partition between the said compartment and the remainder of the airplane whereby the compartment is substantially air tight except for said aperture; said means including a door for ingress and egress, the door being latched and rearwardly hinged, the hinges being releasable: whereby the positive airpressure built up within the said compartment by airspeed will not only facilitate opening but will jettison the door -when released for safe egress by the gunner while in flight.

17. In an airplane having a pilot position; a gunner compartment in the nose of said airplane, the compartment being apertured into the positive pressure area; means including a partition between the said compartment and the said position whereby the compartment is substantially air tight except for said aperture; said means also including a gun turret wall, at least a portion of the wall being transparent as well as aligned with the pilot position, and a door for ingress and egress, the door being latched and rearwardly hinged, the hinges being manually releasable: whereby the gunner may visually communicate with the pilot in preparation for leaving his compartment, and whereby the positive airpressure built up within the said compartment by airspeed will not only facilitate opening but 'will jettison the door for safe egress by the gunner while in flight.

DREW M. HELWIG. 

